Line chart is very slow in IE8

We are prototyping with GXT3.0DP5 + GWT2.4.0 and trying to take advantage of GXT new chart feature that doesn’t require Flash or other plugin. The line chart we had was coming from GXT Demo code from GXT SDK with some minor modification, e.g. creating line chart data with a different Java file. We first sent all our chart data to the browser to display small versions of all charts which work like thumbnails and then when clicking on one of the thumbnails, it displayed a full-size chart under the thumbnails. This worked very well in Firefox and Chrome - since the data are already in the browser, it opened up immediately, but for IE8, it took 5 to 10 seconds to paint a full-size chart.
We are all new GXT users, so we are not sure whether this is our setting issue or simply a bug in GXT chart. Could someone help us? Thanks!

Development Environment: IntelliJ 10.5.2 + GXT3.0DP5 + GWT2.4.0
The test was run in non-debug mode.

More info

I appreciate whoever tried to reply my question, but please try not to use Arabic and point it to a pron site. I know a few languages, but Arabic is not one of them.

Forgot to mention that we also did live update every 15 seconds. Having about 4 charts 2 series each and 32 data points for each series, IE simply couldn't handle it and displayed "Stop Script" messsage everytime when charts were updated.

I also did a test with Live Chart out of demo and brought up scrollbar to see how IE handled scrolling when doing live update. It delayed significantly comparing to Firefox and Chrome.

We’ve seen this pop up from time to time. Because this is still only a beta release, we haven’t had time to fine-tune the performance of the library. As a result, you may find that you have to disable some features, such as shadows or animations, while Ext GWT is still in beta. This is especially true with browsers in the Internet Explorer family. Once Ext GWT leaves beta, you can turn these features on and re-evaluate.

An API concern

Thank you for your reply. I've tried IE9 and with some minor code adjustment I could get it to work like Firefox and Chrome.
One concern we have is that when Sencha can finalize GXT3.0 APIs. Will we expect to see many API changes in the final release?

At least for the gxt-chart project I can promise that the API will be finalized for Beta 2. The only reason I would need to change anything would be if it became necessary for performance improvements. However, that most likely would not affect anything public.